In the prior art, a configuration of distributed servers in a network comprises a control server and a two or more resource servers that are coupled to the control server. The control server assigns or allocates processing tasks to the resource servers, which then perform the task.
Each processing task requires each resource server to which it is assigned, to process or handle the task for, or on behalf of, the network. In a telecommunications network, a processing task that a resource server would perform includes the processing of incoming telephone or cellular telephone calls.
To prevent a single resource server, such as an application server in a cellular communications network, from becoming overloaded and thereafter delaying or denying call attempts by customers or even worse, dropping calls in progress, the control server performs processing load balancing by which it attempts to evenly distribute the processing loads among the various resource servers.
Prior art methods exist for load balancing, but regardless of how load balancing is performed, a load balancing problem can arise when two or more resource servers appear to the control server to be equally suited (or unsuited) to accept additional data processing loading. Deciding which of two or more servers a new load should be sent to requires tie breaking between two or more resource servers that appear to be equally able or unable to handle an additional processing task.
Prior art tie resolution methods consider a resource server's base line or normal loading. In a telecommunications network, prior art tie resolution considered calls-in-progress or CIP; current overload state and call gap percentage in the current overload state but when resolving ties, they do not consider the overall performance of the network.
The terms and concepts of “call gap,” “call gapping” and “call gapping percentage” used through-out this disclosure, are explained in the applicant's co-pending U.S. patent application having Ser. No. 11/173,412 and entitled, “APPLICATION LOAD LEVEL DETERMINATION” and which was filed on Jun. 30, 2005. The teachings of application Ser. No. 11/173,412 regarding the concepts and meanings of terms of “call gap,” “call gapping” and “call gapping percentage” are incorporated herein by reference.
The terms and concepts of “normal load” state/condition, “overload” and “overload state” used through-out this disclosure are explained in the applicants co-pending U.S. patent application having Ser. No. 11/171,077 and entitled “CONTROL SERVER THAT MANAGES RESOURCE SERVERS FOR SELECTED BALANCE OF LOAD” which was filed on Jun. 30, 2005. The teachings of application Ser. No. 11/171,077 regarding the concepts and meanings of normal load state or condition, “overload” and “overload state” are hereby incorporated herein by reference.
Prior art tie resolution methods do not always properly allocate a new processing load between two or more apparently-equally qualified servers because the servers might not, for various reasons be equally appropriate for assigning new load tasks to them nor do prior art methods consider network performance overall. Since it's well known that the quality of service (QoS) in a network is affected by the computers/servers of a network that control and operate network equipment, in order to maintain service levels in a network, a need exists for a method of resolving ties between resource servers whereby a control server can assign a new processing load to the resource server best suited to handle the load for the best overall operation of a communications system or network.